Compared to double or multi-skinned combustors, a single skin design has the potential to be lighter in weight and hence lower in cost. However, current effusion cooled liner designs are limited in efficiency due to manufacturing constraints such as hole size and angle. Therefore, without increasing cooling air consumption, additional heat removal is a challenge. In aviation gas turbine engines, it is desirable that the amount of air supplied for cooling combustor walls be minimized in order not to negatively affect the overall performances of the engine. This poses challenges to meeting the durability requirements of single skin combustor walls, because the reduction in combustion wall cooling air may lead to unwanted material oxidation, thermal mechanical fatigue and/or thermal wall buckling due to thermal gradients. Particularly in small aero gas turbine engines, the total amount of air available for combustor wall cooling within the gas turbine thermodynamic cycle can be limited, especially where rich-burn combustion is sought. Therefore, it is a challenge to optimize the combustor wall cooling while still meeting the durability requirements of single skin combustors.